Texas Instruments LM2661/3/4EVAL/NOPB

Overview

LM2661/3/4EVAL/NOPB from Texas Instruments is an evaluation board supporting three CMOS charge-pump voltage converters-LM2661 (voltage doubler/inverter, VSSOP-8), LM2663 (inverter, SOIC-8), and LM2664 (inverter, SOT23-6)-each configured for independent operation with manual shutdown jumpers, fixed internal oscillators (80/150/160 kHz), and optimized low-ESR ceramic capacitor networks. It enables rapid validation of ±VIN or 2×VIN generation in space-constrained portable power rails.

For engineers reviewing the LM2661/3/4EVAL/NOPB datasheet, LM2661/3/4EVAL/NOPB pinout, LM2661/3/4EVAL/NOPB application, or LM2661/3/4EVAL/NOPB equivalent, this board provides verified reference designs for dual-mode charge-pump topologies, component selection guidance (e.g., Taiyo Yuden MLCCs), and comparative efficiency/output resistance measurements across all three IC variants under real load conditions.

Technical Context

The board implements three distinct switched-capacitor configurations: LM2661 in voltage-doubling mode (2.5–5.5 V input, 100 mA output, 88% typical efficiency); LM2663 in inverting mode (1.5–5.5 V input, 200 mA output, 86% efficiency); and LM2664 in inverting mode (1.8–5.5 V input, 40 mA output, 91% efficiency). Each uses dedicated 1206-footprint ceramic capacitors matched to its oscillator frequency and output impedance.

All three circuits include manual ON/OFF jumpers (J1–J3), require no external clock source, and rely on internal oscillator control-LM2661/LM2663 support external capacitor-based frequency adjustment, while LM2664 operates at a fixed 160 kHz. Output ripple is measured ≤75 mV_PP at 40 mA for LM2664, confirming low-noise performance suitable for op-amp biasing and interface supplies.

Key Specifications

Availability

LM2661/3/4EVAL/NOPB is available at Aetrix Electronics and suitable for portable medical instruments, handheld test equipment, battery-powered op-amp supplies, and low-noise interface power rails requiring stable component supply and validated reference design implementation.

Supply support for LM2661/3/4EVAL/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in power management, signal chain, and interface solutions for industrial, automotive, and consumer applications.

The LM2661/3/4EVAL/NOPB belongs to TI's switched-capacitor voltage converter evaluation platform family, designed to accelerate prototyping of compact, inductorless DC/DC conversion for space- and EMI-sensitive applications such as portable instrumentation and interface power domains.

FAQ

What is the primary function of the LM2661/3/4EVAL/NOPB evaluation board?

The LM2661/3/4EVAL/NOPB evaluation board provides a ready-to-use platform for testing and validating three distinct TI charge-pump ICs: LM2661 (doubler/inverter), LM2663 (inverter), and LM2664 (inverter). Each device operates independently with dedicated input/output headers, shutdown jumpers, and optimized capacitor networks. The board allows engineers to verify voltage conversion efficiency, output ripple, and startup behavior without custom PCB design-making it ideal for early-stage power architecture exploration.

Which charge-pump ICs are supported on the LM2661/3/4EVAL/NOPB and what are their key differences?

The LM2661/3/4EVAL/NOPB supports LM2661 (VSSOP-8, 80 kHz, up to 100 mA), LM2663 (SOIC-8, 150 kHz, up to 200 mA), and LM2664 (SOT23-6, 160 kHz, up to 40 mA). Differences include package size, output current capability, input voltage range (LM2664 starts at 1.8 V), and oscillator adjustability (LM2661/LM2663 allow external capacitor tuning; LM2664 is fixed). All share shutdown control and low-quiescent-current operation.

Does the LM2661/3/4EVAL/NOPB support external clock synchronization?

No, the LM2661/3/4EVAL/NOPB does not support external clock synchronization. While the LM2661 and LM2663 datasheets indicate external clock capability in standalone use, the evaluation board implements only the internal oscillator for each device-80 kHz for LM2661, 150 kHz for LM2663, and 160 kHz for LM2664. No external clock input pins are routed or terminated on the board.

What capacitor types and values are used on the LM2661/3/4EVAL/NOPB and why?

The LM2661/3/4EVAL/NOPB uses Taiyo Yuden multi-layer ceramic capacitors: 22 µF (EMK432BJ226MM) for LM2661, 10 µF (JMK316BJ106ML-T) for LM2663, and 3.3 µF (LMK316BJ335ML-T) for LM2664-all in 1206 footprint. These were selected for low ESR (≈25 mΩ for LMK part), stable temperature/frequency response, and optimal ripple suppression per device's oscillator frequency and output resistance requirements.

Can the LM2661/3/4EVAL/NOPB be used to evaluate both voltage inversion and doubling topologies?

Yes-the LM2661/3/4EVAL/NOPB is configured to demonstrate both functions: LM2661 is wired in voltage-doubling mode (requiring one external Schottky diode), while LM2663 and LM2664 are wired in inverting mode. The board's schematic (Figure 1 in AN-1142) confirms these configurations, and the user guide explicitly states that LM2661 can also invert when reconfigured externally-though that alternate topology is not pre-assembled on the board.